The structure and the resulting operational data of bearing bushings that are used in a chassis of a motor vehicle may have an influence on the driving and steering characteristics of the motor vehicle. Relatively minor changes to a spring constant or stiffness of the bearing bushings can have considerable effects on the vehicle characteristics, such as for example the understeer or oversteer characteristics and chassis noises, vibrations and running harshness. Depending on the setting of the bearing bushing, the motor vehicle has a relatively “soft” or relatively “hard” running characteristic.
The generally known prior art has disclosed various bearing bushings in the chassis region of a motor vehicle. Firstly, purely mechanical bearing bushings or rubber bearings are known which have a defined stiffness. Furthermore, hydraulically damped chassis bushings with fixed or variable stiffness are known. Furthermore, bearings with magnetorheological liquids or magnetorheological elastomers are known, wherein the stiffness can be varied by means of a magnetic field.
For example, DE 696 22 141 T2 discloses a method for producing and using a suspension bushing with variable stiffness for controlling the relative movement between a suspension link in a motor vehicle and a frame component of the motor vehicle. The suspension bushing has a variable stiffness, which is realized by virtue of the fact that there is an enclosed magnetorheological elastomer or gel, the stiffness of which is variably adjustable over a wide range, specifically by means of a controllable magnetic field. The variable controllable magnetic field is generated by means of an electromagnetic structure which is completely integrated, as part of the structure, into a suspension bushing structure.